Adjustable support for furniture and the like



March 29, 1949.

cfR. NALLE 2,465,741 ADJUSTABLE SUPPORT FOR FURNITURE AND THE LIKE FiledFeb. 4, 1948 7am 2".' (whiz/110 75 9MAWS 25 W/fiww/V Patented Mar. 29,1949 ADJUSTABLE SUPPORT FOR FURNITURE AND THE LIKE Charles R. Nalle,Philadelphia, Pa.

Application February 4, 1948, Serial No. 6,273

This invention relates to the construction and manufacture of adjustablefurniture supports. The present invention is an improvement upon theadjustable support disclosed in my co-pending application Serial No.575,625 and also includes details in the fabrication of such a supportwhen the base member is made of a compression molded plastic.

Some articles of furniture, particularly refrigerators, stoves andwashing machines, have sheet metal leg construction which enables thelocking device of an adjustabe support to be installed after thethreaded stem of the support has been turned through the leg base. Inthe case of Wooden furniture, where the support is used in a blind hole,the locking device in some constructions is inserted first, then astationary threaded member attached to the leg, whereupon the threadedstem of the caster or glide is inserted through the threaded base andlocked in the retainer. In other blind hole constructions, the stem maybe inserted partially through a metal plate whereupon the retainer isinstalled and then the metal plate fastened to the furniture by means ofscrews or other similar devices in which event it is possible to installthe retainer on the stem of the glide manually and the presentconstruction is equally adapted to this expedient as well. The presentconstruction contemplates the use of an internally threaded nut orsupporting member which may be welded or integrally formed in themetallic leg of a refrigerator or stove, for example, and also which maybe attached to the leg of a piece of wooden furniture. The retainerconstruction and the shape of the stem are such that the retainer may bereadily installed and is maintained in locking relation with respect tothe stem so that the stem may not be completely disengaged from thethreaded member by unscrewing the stem. Furthermore, when the threadedportion of the stationary threaded member is of standard thickness, thedistance from the first thread on the glide stem to the abutting portionof the retainer may be controlled to provide spring loaded contactbetween the stem and the stationary support.

I have found that a synthetic plastic base element for a glide has manyadvantages over a metallic 'base, since articles such as refrigerators,stoves, etc., are customarily placed on floors which require frequentwashing. The strong chemicals used in washing solutions quickly corrodethe metallic bases thus leaving a permanent stain on the floor surface.In addition, even 8 Claims.

2 though a non-ferrous metallic base be used to avoid rust, such metalsordinarily leave a mark on the floor when the artice of furniture ismoved. The provision, therefore, of a rigid plastic base for the glidewhich will not stain or mark the floor surface either from rust or fromfrictional contact therewith, is a distinct advantage.

The molding of a plastic base for such a glide has presented, however,particular difficulties due to the fact that the plastic material has atendency to seep into the threaded stem during the molding process. Thisnecessitates a thread cleaning operation which is expensive and costsmuch more than the articles themselves.

A primary object of the invention, therefore, is to provide a left-handhelical spring retainer for an adjustable furniture support, the body ofthe spring retainer being of greater diameter than the diameter of thestem and the ends of the retainer being of small enough diameter toextend into the threaded stem support.

A further object of the invention is to provide a rigid syntheticplastic base for a furniture glide.

A further object of the invention is to provide a stem of the typedescribed, in which the axial distance between the first thread and theretainer shoulder is slightly less than the thickness of the internallythreaded support member.

A still further object is to provide a flange on the lower end of thestem which acts as a seal during the molding operation of the plasticbase element.

Further objects will be apparent from the specification and drawings inwhich:

Fig. 1 is an elevation showing my improved adjustable support installedin the leg of a sheet metal article of furniture;

Fig. 2 is an enlarged sectional detail of the stem showing the retainerjust abutting the threaded nut;

Fig. 3 is a view similar to Fig. 2 but with the threads of the stemcompletely disengaged from the nut, thereby distending the retainer;

Fig. 4 is a sectional view showing the stem in position in the mold;

Fig. 5 is an end view of the helical spring retainer; and

Fig. 6 is a side elevation of the helical spring retainer.

An ad ustable support designated generally at H) has a plastic base Hwhich is molded on the stem l2. In operation, the support is adapted tobe threaded into a nut or internally threaded burr l3 which may bewelded to the bottom I4 of a metallic furniture leg l5. It will beapparent 3 that if the thickness of the bottom web Id of leg I5 issufficient, the nut may be dispensed with and the threads may be cut inweb M itself.

Previous practice in an adjustable support of this type has been toutilize a plain threaded stem with no retainer and then upset the end ofthe stem by means of a cold chisel or hammer after the stem has beenthreaded through nut I 3. The objections to this procedure have beenthat the end of the stem is extremely inaccessible for such an upsettingoperation and unless extreme care be used, the stem is bent to such anextent that it does not turn freely in nut [3 or it is no longervertical, thus preventing full contact of base member II with the floor.Furthermore, when a cold chisel is employed for the upsetting operation,the chisel frequently slips, causing the leg to be disfigured or thepaint to be chipped.

I provide the end of the stem with a frustoconical nose l6 which has adual purpose of facilitating appl cation of the spring retainer l1 andalso assists in removal of the stem during the molding operat on as willbe explained hereinafter. The largest diameter of tapered nose I6 iscons derably less t an the dr lled diameter of nut l3 and forms a shouler I8 aga nst which t e first convolution or coil of helical spring Hseats. From thence the stern diameter gradually increases to the appoximate root d ameter of t e thr aded shank l9 as shown in Figs. 2 and3, to form a second larger frusto-conical area. Threaded shank l9terminates at shoulder 20 and a knurled port on 2| on the ste ncompletes the construction of this member (Fig. 4)

In the manufacture of t e stem proper, a ro ling op ration is util zed troughout, both for nose l6 as well as threaded port on l9. After the sten has been completed, t is dropped into the middle sect on 25 of a moldwhich is comprised of a lower sect on 26 and an upper section 21. Inpractice, the mold 25 s adapted to accommoda e a lar e number of stemsfor pro-" duc on ork. Mo d 25 as well as mo d 26, have a bo e 8 adaptedto rec ive threaded ste n IS.

The d ameter in bore 28 has be n found to be of crit cal im o tance inpreve ing lost time dur n t e mo d n op ation. I t e d ameter o bo e 28p ov d s a c o fit w t t e. outs de dia eter of t rea ed portion IQ ofthe stem, it has been found poss ble to reduce the danger of the. moling co ound. 29 bein forced into bore 28 n t e moldin p o ess. Th sohiecti e is ir orta t eca se an co o nd w c gets i o t eads in must hea d by hand before t e stem can he used. Howev r, it was found that an atempt to control the tolerances of a rol ed t read to t e ex ent t at aclose fit in bore 28 could be p ovided. increased the cost of product onexcessively. Furthermore, it became. necessary toknock out each stemfrom the mold individually, both when the stem itself was slightlyoversize and also When a slight amount of compound found its way intothe upper part of bore 28.

I have solved this problem by substant ally increasing the diameter ofbore 28 so that stem l9 always has a loose fit therein, regardless ofthe rolling tolerances, and provid ng in addition a shoulder 20 on thestem to act as a pressure seal, thus preventing any compound 29 fromentering bore 28. Thus the shoulder of flange 20 not only acts as a sealto prevent clogged threads. but also enables the bore 28 of the mold tobe increased to the point where the completed glides It) can be removedfrom the mold merely by turning the mold over.

A further advantage of the construction resides in the fact that if forany reason it becomes necessary to drive the stems from the mold, nosel6 serves as a suitable means by which the glides can be removed fromthe mold portion 25 after lower mold 26 has been disconnected. Poundingon nose I6 cannot injure threads l9 as would be the case if the threadswere carried the extreme length of the stem.

Referring now to Figs. 2 and 3, the construction of the retaining memberI! is of particular importance. First, the opposite ends of the retainerare identical so that it may be inserted with either end up; secondly,the diameter of the first convolution 30 of the spring is suflicient toseat tightly behind shoulder l8 of nose 16 but at the same time must belarge enough so that the retainer may be readily pressed over theshoulder. When the stem has been unscrewed to the position shown in Fig.2 in which about one thread on the stem remains in engagement with thethreads on nut I3, the first large convolution 3| of the retainercontacts the face 32 of the nut l3. In this posit on, convolution 30 haspartially entered the bore of the nut and it is for this reason that thediameter of shoulder l8 must be small enough to provide suflicientclearance between shoulder l8 and the threads in the nut, so that thereis no danger of .iamming the retainer in the threads. Further withdrawalof stem l9 so that the threads are completely disengaged, as shown inFig. 3, places the first convolution of the retainer in tension, thuscreating a pressure between the bottom of the nut l3 and the firstthread on portion IS. The pressure thus created must be insufiicient todisengage convolut on 30 from shoulder l8 but at the same time must beample to counterbalance the weight of the glide I0. Obviously, thethickness of nut I3 is the controlling factor in achieving this resultand it will therefore be apnarent that the thickness of the nut when thestem is in the position of Fig. 2 should be such that between one-halfand one turn will completelv disenga e the threads. When the stem isunder the sl ght tension caused by complete t ead disen agement, it isonly necessary to rotate the lide. ill in a clockw se d rection toinsure ret reading. If such tens on were absent, it ould be necessary topush up ardly on the glide in o der to en age the threads thus the provs on of such tension is of distinct advantage. In add t on. theresistance to complete d sengaeement of the stem is desi able inpreventing excessive tu ning when a piece of furniture is be moved.

For e ample. in a stern having a threaded s ank 1%" in diameter and' 18t r ads Der inch, I have found that the desired resu ts enumerated abovecan be achieved w en the distance from t e shoulder formed by the noseHi to the first thread on t e stem is A", the diameter of the shoulder.190", the net diameter of the stem just behind the shoulder thethickness of the nut or threaded member s s", and the spring wireforming the retainer .036".

The retainer I! is wound in a left-hand or counter-clockwise manner sothat there will be no tendency for the convolutions of the retainer tobecome wedged in the internal threads of nut 13 as might likely be thecase with a right-hand spring when in the position shown in Fig. 3.

It will thus be apparent that I have provided an adjustable stem forfurniture supports whether of the glide or caster type, which permitsextremely low cost production and at the same time eliminates manyserious disadvantages of prior constructions. In practice, the cost ofthe material for manufacturing the glides is so negligible that oneextra operation may double or triple the cost of the finished product.It is therefore of extreme importance that the design of the stem besuch that close manufacturing tolerances are unnecessary and at the sametime an efificient, durable product is obtained.

I claim:

1. A stem for an adjustable furniture support comprising a threadedshank, a shoulder at one end of said shank, the diameter of the shoulderbeing substantially greater than that of the shank, a knurled extensionterminating the stem, said shoulder being located between the extensionand the shank, a double tapered nose at the opposite end of the stem,and a second shoulder between said tapered noses, the diameter of saidsecond shoulder being less than the root diameter of the threaded shank.

2. An adjustable support assembly for furniture and the like, comprisingan internally threaded member attached to the leg of an article offurniture, an adjustable support having a stem, a threaded shank on saidstem adapted to engage said threaded member, a floor-engaging elementattached to the bottom of said stem, a tapered nose formed at the top ofsaid stem, said nose terminating in a shoulder in spaced relation to theupper terminus of the threads on the shank, a helical spring retainerformed by a length of spring wire wound in the opposite direction fromthe threads on the shank, a restricted convolution at each end of saidretainer, said restricted convolution adapted to be expanded over andretained behind the shoulder on the stem.

3. Apparatus in accordance with claim 2, in which the distance betweenthe shoulder on the stem and the first thread on the shank is such thatwhen the threaded shank is unscrewed in the threaded member, a largeconvolution of the retainer abuts the upper surface of said threadedmember, and the restricted convolution of the retainer enters into thebore of the threaded member.

4. Apparatus in accordance with claim 2, in which the maximum diameterof the shoulder on the stem is less than the drill diameter of thethreaded member minus twice the diameter of the spring wire forming theretainer.

Apparatus in accordance with claim 2, in which the diameter of centerconvolutions of the retainer is greater than the drill diameter of thethreaded member and the outside diameter of the end convolutions is lessthan the drill diameter of the threaded member.

6. Apparatus in accordance with claim 2, in which the relation betweenthe distance from the shoulder to the first thread on the shank and thedistance from the first center convolution of the retainer to theshoulder when the retalner is in place on the stem is such that thedistance from said first center convolution of the retainer to the firstthread on the shank is less than the thickness of the threaded portionof the internally threaded member attached to the furniture leg.

7. An adjustable glide member for furniture and the like comprising athreaded shank portion, a knurled portion at one end of the stem, aflange between the knurled portion and the threaded portion, thediameter of the flange being substantially greater than that of theshank, a double tapered nose at the opposite end of the stem, a shoulderbetween said tapered noses, the diameter of said shoulder being lessthan the root diameter of the threaded shank, and a synthetic plasticsupporting element rigidly molded around said knurled portion of thestem.

8. A retainer construction for threaded members and the like comprisinga helical spring having center coils of greater diameter than thediameter of the threaded member, a coil of reduced diameter ateach endof the retainer and formed integrally with the center coils from alength of spring wire, the diameter of the reduced coils adapted to fitover an annular shoulder on the extremity of the threaded member.

CHARLES R. NALLE,

No references cited.

